1
Name __________________________________ Lab Section _________
Control of Microbial Growth – U.V. Radiation – Results & Interpretation - (12 pts) – You will
hand this section in on the designated date.
Results – Use the images in the “Control of Microbial Growth-UV radiation - RESULTS"
document to complete the table below. (8 pts – 0.5pt each space)
1. According to your results, can U.V. radiations penetrate an index card? Explain your answer.
(1.5 pts)
2. Which of the two organisms tested are more resistant to U.V. radiation? (1 pt)
What might explain their greater resistance to U.V. radiation? (i.e. maybe a structure they possess)
Explain thoroughly! (1.5 pts)
15 seconds
UV exposure
30 seconds
UV exposure
1 minute
UV exposure
2 minutes
UV exposure
No
cover
Covered
No
cover
Covered
No
cover
Covered
No
cover
Covered
E. coli
B. cereus
Alexa Campanella
S
+++
+++
+
+++
0
+++
0
++
+++
++
+++
+
+++
0
+++
+++
Based on the results, U.V. cannot penetrate an index card because all covered growths had
a rating of "+++" for every time of U.V. exposure.
B. cereus
B. cereus posesses endospores which plays a role in the heat resistance. Endospores are
resistant to harsh environments to protect bacteria.
